Evaluation of patients labeled with a penicillin allergy to promote antimicrobial stewardship in dental practice

BACKGROUND

Approximately 10% of the US population self-reports a penicillin allergy history or are labeled as penicillin allergic. However, from 90% through 99% of these patients are not allergic on formal evaluation.

CASE DESCRIPTION

Patients labeled as penicillin allergic receive broader-spectrum and sometimes less-effective antibiotics, thereby contributing to increased treatment failures, antibiotic resistance, and adverse drug reactions. Self-reported penicillin allergy can be eliminated or classified as low-, medium-, or high-risk after a careful review of patient history. This allows these patients to be delabeled; that is, having any reference to their penicillin allergy history or of having an allergy to penicillin eliminated from their health records.

PRACTICAL IMPLICATIONS

Oral health care professionals are ideally placed to partner in both antibiotic stewardship interventions by means of recognizing pervasive mislabeling and aiding in the process of delabeling.

Role of tcaA, a potential target as a ceftobiprole resistance breaker, in MRSA β-lactam resistance

OBJECTIVES

Using a random forest algorithm, we previously found that teicoplanin-associated gene A (tcaA) might play a role in resistance of methicillin-resistant Staphylococcus aureus (MRSA) to β-lactams, which we have investigated further here.

METHODS

Representative MRSA strains of prevalent clones were selected to identify the role of tcaA in the MRSA response to β-lactams. tcaA genes were deleted by homologous recombination in the selected MRSA strains, and antibiotic susceptibility tests were applied to evaluate the effect of tcaA on the minimum inhibitory concentrations (MICs) of glycopeptides and β-lactams. Scanning electron microscopy, RNA sequencing, and quantitative reverse transcription-polymerase chain reaction were performed to explore the mechanism of tcaA in MRSA resistance to β-lactams.

RESULTS

The MIC of penicillin plus clavulanate decreased from 3 mg/L to 0.064 mg/L and that of oxacillin decreased from 16 to 0.5 mg/L when tcaA was knocked out in the LAC strain. Compared with wild-type MRSA isolates, when tcaA was deleted, all selected strains were more susceptible to β-lactams. Susceptibility to ceftobiprole was restored in the ceftobiprole-resistant strain when tcaA was deleted. tcaA knockout caused "log-like" abnormal division of MRSA, and tcaA deficiency mediated low expression of mecA, ponA, and murA2.

CONCLUSIONS

Machine learning is a reliable tool for identifying drug resistance-related genes. tcaA may be involved in S. aureus cell division and may affect mecA, ponA, and murA2 expression. Furthermore, tcaA is a potential resistance breaker target for β-lactams, including ceftobiprole, in MRSA.

Case report: Methicillin-resistant Staphylococcus aureus with penicillin susceptible (PS-MRSA): first clinical report from a psychiatric hospital in China

This case report documents the first instance of Penicillin-Susceptible Methicillin-Resistant Staphylococcus aureus (PS-MRSA) in a Chinese psychiatric hospital. The strain was isolated from a patient with Alzheimer's disease who had a lower respiratory tract infection. Clinical and laboratory analyses, including mass spectrometry, antibiotic susceptibility testing, and whole-genome sequencing, confirmed the PS-MRSA strain. In this case, we systematically introduce the clinical symptoms, laboratory findings, and treatment responses associated with this PS-MRSA strain. This discovery offers a new perspective on our understanding of resistance mechanisms and expands our considerations for existing antibiotic treatments. It may fill a gap in the classification of MRSA strains, enhance the spectrum of MRSA resistance, and complete the therapeutic strategies for MRSA.

Animal drug shortages limit veterinary therapeutic options and introduce artifacts in antimicrobial sales reporting

Supply chain issues disrupt veterinary care and cause downstream consequences that alter the practice of veterinary medicine. Antimicrobials are just 1 class of pharmaceuticals that have been impacted by supply chain issues over the last couple of years. Since February 2021, 2 sponsors/manufacturers of penicillin products have reported shortages in the active pharmaceutical ingredient. With the release of the 2021 Summary Report on Antimicrobials Sold or Distributed for Use in Food-Producing Animals by the FDA, a key finding was a 19% decrease in penicillin sales and distribution from 2020 to 2021. Herein, we provide our clinicians' professional perspective regarding how drug shortages, specifically that of penicillin, might contribute to misconstrued patterns in antimicrobial use and what can be done by veterinarians and the FDA to minimize the impact of an antimicrobial drug shortage on animal health and well-being.

Antimicrobial-associated encephalopathy due to ampicillin

Because the β-lactam ring has a molecular structure similar to that of gamma-aminobutyric acid (GABA) neurotransmitters, it binds to GABA A receptors and inhibits GABAergic transmission, causing AAE. The possibility of antimicrobial-associated encephalopathy should be considered in cases of neurological or psychiatric symptoms after initiating an antimicrobial regimen.

Adherence to penicillin treatment is essential for effective secondary prevention of rheumatic heart disease: a systematic review and meta-analysis

Background

Penicillin is essential for secondary prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). However, the incidences of ARF recurrence and RHD progression remain high, particularly in endemic countries. This meta-analysis evaluated the effectiveness of penicillin adherence in secondary prevention of ARF recurrence and RHD progression.

Methods

The authors included original articles employing an observational study design in which the study population included patients with ARF or RHD and documented adherence to secondary prophylaxis with penicillin for secondary prevention. Systematic searches of the PubMed, Scopus, and Cochrane databases were performed. Moreover, the authors also conducted a snowballing literature search from Europe PMC to expand the included studies. The quality of each study was assessed using the National Institute of Health Quality Assessment Tool. The statistical analyses were conducted using Review Manager 5.4.1 software developed by Cochrane. In addition, the authors utilized pooled odds ratios (ORs) to compare the adherence techniques.

Results

A total of 310 studies were identified, of which 57 full-text articles were assessed for eligibility. The authors included six studies with 1364 patients for the qualitative synthesis and meta-analysis. Good adherence to penicillin for the secondary prophylaxis of ARF and RHD, significantly reduced the odds of ARF recurrence or RHD progression by up to 71% compared to that associated with poor adherence [pooled OR 0.29 (0.21-0.40); I²=0% (p=0.56); Z=7.64 (p <0.00001)].

Conclusion

Good adherence to penicillin for secondary prophylaxis in patients with ARF or RHD is essential for reducing the risk of ARF recurrence or RHD progression.

Syphilis Treatment: Systematic Review and Meta-Analysis Investigating Nonpenicillin Therapeutic Strategies

Background

Penicillin's long-standing role as the reference standard in syphilis treatment has led to global reliance. However, this dependence presents challenges, prompting the need for alternative strategies. We performed a systematic literature review and meta-analysis to evaluate the efficacy of these alternative treatments against nonneurological syphilis.

Methods

We searched MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane, Scopus, and Web of Science from database inception to 28 August 2023, and we included studies that compared penicillin or amoxicillin monotherapy to other treatments for the management of nonneurological syphilis. Our primary outcome was serological cure rates. Random-effect models were used to obtain pooled mean differences, and heterogeneity was assessed using the I2 test.

Results

Of 6478 screened studies, 27 met the inclusion criteria, summing 6710 patients. The studies were considerably homogeneous, and stratified analyses considering each alternative treatment separately revealed that penicillin monotherapy did not outperform ceftriaxone (pooled odds ratio, 1.66 [95% confidence interval, .97-2.84]; I2 = 0%), azithromycin (0.92; [.73-1.18]; I2 = 0%), or doxycycline (0.82 [.61-1.10]; I2 = 1%) monotherapies with respect to serological conversion.

Conclusions

Alternative treatment strategies have serological cure rates equivalent to penicillin, potentially reducing global dependence on this antibiotic.

Penicillin allergy reassessment for treatment improvement: A dental office tool to support appropriate penicillin allergy labeling

BACKGROUND

Dental appointments offer an opportunity to evaluate a documented penicillin (PCN) allergy and determine whether the patient might be a candidate for medical reassessment of their allergy. The authors gathered feedback on the Penicillin Allergy Reassessment for Treatment Improvement (PARTI) tool, designed to enhance dentist-patient communications regarding PCN allergies.

METHODS

From January 2022 through May 2023, the authors conducted a mixed-methods study, collecting focus group data from patients with PCN allergies and surveying health care workers (HCWs) regarding the PARTI tool. Feedback focused on reassessment procedures, patient-centered allergy information, and medical records updates. Thematic analysis was used for focus group data.

RESULTS

The study included 15 patients in focus groups and 50 HCW survey respondents representing diverse US regions. Patient demographic characteristics included varied races, the mean age was 52 years, and most of the patients were female (53.3%). Most patients had health care interactions within the preceding year, at which 86.6% of patients were asked about drug allergies. HCW respondents primarily consisted of pharmacists (30%) and dentists, dental hygienists, and dental assistants (28%). Feedback on the PARTI tool was constructive, with both patients and HCWs recognizing its potential benefits and providing insights for improvement. Many HCWs (68%) highlighted the importance of step 3 of the PARTI tool, that is, the section on PCN allergy testing. Feedback from participants was incorporated into the final PARTI tool.

CONCLUSIONS

Patient and HCW feedback on the PARTI tool was used to finalize a tool for the dental office to provide to patients who are candidates for PCN allergy reassessment. The feedback will also be used to inform an upcoming pilot study in US dental offices, focused on the process for PCN allergy reassessment and health record documentation.

PRACTICAL IMPLICATIONS

Deploying the PARTI tool in dental offices is pivotal, as mislabeling patients with PCN allergies could have severe consequences, such as hindering the prescription of lifesaving antibiotics for conditions like endocarditis, in the future. This implementation not only enhances communication between dentists and patients, but it is also crucial for ensuring improved patient safety and maintaining accurate medical records among health care settings.

Full-dose challenge of moderate, severe, and unknown beta-lactam allergies in the emergency department

OBJECTIVE

This study aims to assess the outcome of challenging documented moderate, severe, or unknown beta-lactam allergies with full dose administration of a beta-lactam antibiotic in emergency department (ED) patients admitted for acute bacterial infection.

METHODS

A single-center, retrospective, descriptive study of adult patients challenged with a full dose of beta-lactam in the ED from January 2021 to December 2022 was conducted. Included patients had at least one documented moderate, severe, or unknown beta-lactam allergy in the electronic medical record (EMR) without documentation of prior tolerance. Patient demographics, prior beta-lactam antibiotic reaction, beta-lactam administered in the ED, inpatient beta-lactam continuation, adverse drug reactions, and updates to allergy profiles were collected. Descriptive statistics for data analysis were performed using SPSS Version 22.

RESULTS

Of the 184 ED encounters with full-dose beta-lactam challenges, five (2.7%) patients with documented moderate, severe, or unknown beta-lactam allergies experienced an allergic reaction after the challenge; one (0.5%) patient had an allergic reaction in the ED, and the remaining four (2.2%) occurred after admission. No anaphylactic reactions occurred. All allergic reactions were limited to mild rash or itching. Most patients (98.9%) were challenged with a cephalosporin. A beta-lactam was continued in 86.4% of cases, and the allergy profile was updated for future utilization in 73.4% of patients.

CONCLUSIONS

This study suggests that full-dose challenge of moderate, severe, or unknown beta-lactam allergies can be safely accomplished in the ED. This approach avoids unnecessary penicillin allergy skin testing and reduces utilization of suboptimal alternative antibiotic regimens.

Barriers to and Facilitators of Delabelling of Antimicrobial Allergies: A Qualitative Meta-synthesis

Background

Patients who report penicillin allergies may receive alternative antibiotics. Such substitution contributes to antimicrobial resistance, lower treatment efficacy, increased frequency of adverse events, and increased costs. Approximately 90% of individuals who report a penicillin allergy can tolerate a penicillin.

Objective

To identify the barriers to and facilitators of removal by health care workers of inaccurate antimicrobial allergies from patient records, known as delabelling.

Data Sources

The MEDLINE database was searched from inception to December 29, 2020.

Study Selection and Data Extraction

Qualitative studies evaluating health care professionals' perceptions of barriers to and/or facilitators of the act of delabelling a patient's antimicrobial allergies were included in the meta-synthesis.

Data Synthesis

The Theoretical Domains Framework was used to code and group individual utterances from the included studies, which were mapped to the Behaviour Change Wheel and corresponding intervention function and policy categories.

Results

Four studies met the inclusion criteria. Eight themes were identified as representing barriers to delabelling: delabelling skills, patient education skills, knowledge, electronic health records (EHRs), communication frameworks, time, fear about allergic reactions, and professional roles. Behaviour change interventions that may overcome these barriers include education, training, algorithms and toolkits, changes to EHRs, use of dedicated personnel, policies, incentivization of correct labelling, and an audit system.

Conclusions

Eight themes were identified as barriers to delabelling of antimicrobial allergies. Future behaviour change interventions to address these barriers were proposed. Confidence in the findings of this study was judged to be moderate, according to the GRADE CERQual approach.

Rolling the evolutionary dice: Neisseria commensals as proxies for elucidating the underpinnings of antibiotic resistance mechanisms and evolution in human pathogens

Species within the genus Neisseria are adept at sharing adaptive allelic variation, with commensal species repeatedly transferring resistance to their pathogenic relative Neisseria gonorrhoeae. However, resistance in commensals is infrequently characterized, limiting our ability to predict novel and potentially transferable resistance mechanisms that ultimately may become important clinically. Unique evolutionary starting places of each Neisseria species will have distinct genomic backgrounds, which may ultimately control the fate of evolving populations in response to selection as epistatic and additive interactions coerce lineages along divergent evolutionary trajectories. Alternatively, similar genetic content present across species due to shared ancestry may constrain existing adaptive solutions. Thus, identifying the paths to resistance across commensals may aid in characterizing the Neisseria resistome-or the reservoir of alleles within the genus as well as its depth. Here, we use in vitro evolution of four commensal species to investigate the potential and repeatability of resistance evolution to two antimicrobials, the macrolide azithromycin and the β-lactam penicillin. After 20 days of selection, commensals evolved resistance to penicillin and azithromycin in 11/16 and 12/16 cases, respectively. Almost all cases of resistance emergence converged on mutations within ribosomal components or the mtrRCDE efflux pump for azithromycin-based selection and mtrRCDE, penA, and rpoB for penicillin selection, thus supporting constrained adaptive solutions despite divergent evolutionary starting points across the genus for these particular drugs. Though drug-selected loci were limited, we do identify novel resistance-imparting mutations. Continuing to explore paths to resistance across different experimental conditions and genomic backgrounds, which could shunt evolution down alternative evolutionary trajectories, will ultimately flesh out the full Neisseria resistome.IMPORTANCENeisseria gonorrhoeae is a global threat to public health due to its rapid acquisition of antibiotic resistance to all first-line treatments. Recent work has documented that alleles acquired from close commensal relatives have played a large role in the emergence of resistance to macrolides and beta-lactams within gonococcal populations. However, commensals have been relatively underexplored for the resistance genotypes they may harbor. This leaves a gap in our understanding of resistance that could be rapidly acquired by the gonococcus through a known highway of horizontal gene exchange. Here, we characterize resistance mechanisms that can emerge in commensal Neisseria populations via in vitro selection to multiple antimicrobials and begin to define the number of paths to resistance. This study, and other similar works, may ultimately aid both surveillance efforts and clinical diagnostic development by nominating novel and conserved resistance mechanisms that may be at risk of rapid dissemination to pathogen populations.

A hope for ineffective antibiotics to return to treatment: investigating the anti-biofilm potential of melittin alone and in combination with penicillin and oxacillin against multidrug resistant-MRSA and -VRSA

Background

The emergence and rapid spread of multi-drug resistant (MDR) bacterial strains, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus (VRSA), have posed a significant challenge to the medical community due to their ability to form biofilm and develop resistance to common antibiotics. Traditional antibiotics that were once effective in treating bacterial infections are now becoming increasingly ineffective, leading to severe consequences for patient outcomes. This concerning situation has called for urgent research to explore alternative treatment strategies. Recent studies have shown that antimicrobial peptides (AMPs) hold promise as effective agents against biofilm-associated drug-resistant infections as well as to enhance the efficacy of conventional antibiotics. Accordingly, we aimed to investigate the antimicrobial and antibiofilm effects of melittin AMP, both alone and in combination with penicillin and oxacillin, against biofilm-forming MDR-MRSA and -VRSA.

Methods

In this study, we investigated the kinetics of biofilm formation and assessed various parameters related to the antimicrobial and antibiofilm efficacy of melittin and antibiotics, both alone and in combination, against MDR-MRSA and -VRSA. The antimicrobial parameters included the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Fractional Inhibitory Concentration Index (FICi), Fractional Bactericidal Concentration Index (FBCi), and the antibiofilm activity of melittin and antibiotics indicated by the Minimum Biofilm Inhibitory Concentration (MBIC), Minimal Biofilm Eradication Concentration (MBEC), Fractional Biofilm Inhibitory Concentration Index (FBICi), and Fractional Biofilm Eradication Concentration Index (FBECi).

Results

The MIC results showed that all S. aureus isolates were resistant to penicillin (≥0.25 μg/mL), and 66% of isolates were resistant to oxacillin. The geometric means of the MIC values for penicillin, oxacillin, and melittin were 19.02, 16, and 1.62 μg/ml, respectively, and the geometric means of the MBC values for penicillin, oxacillin, and melittin were 107.63, 49.35, and 5.45 μg/ml, respectively. The study revealed that the combination indexes of melittin-penicillin and melittin-oxacillin, as determined by FIC values against all isolates, were 0.37 and 0.03, respectively. Additionally, melittin-penicillin and melittin-oxacillin exhibited combination indexes based on FBC values against all isolates at 1.145 and 0.711, respectively. Besides, melittin inhibited the biofilm formation of all S. aureus isolates, with MBIC values ranging from 10 to 1.25 μg/mL, and MBEC values ranging from 40 to 10 μg/mL. Generally, the combination indexes of melittin-penicillin and melittin-oxacillin, determined using FBIC values against all isolates, were 0.23 and 0.177, respectively. Moreover, melittin-penicillin and melittin-oxacillin typically had combination indexes based on FBEC values against all isolates at 5 and 2.97, respectively.

Conclusion

In conclusion, our study provides evidence that melittin is effective against both planktonik and biofilm forms of MRSA and VRSA and exhibits significant synergistic effects when combined with antibiotics. These results suggest that melittin and antibiotics could be a potential candidate for further investigation for in vivo infections caused by MDR S. aureus. Furthermore, melittin has the potential to restore the efficacy of penicillin and oxacillin antibiotics in the treatment of MDR infections. Applying AMPs, like melittin, to revive beta-lactam antibiotics against MRSA and VRSA is an innovative approach against antibiotic-resistant bacteria. Further research is needed to optimize dosage and understand melittin mechanism and interactions with beta-lactam antibiotics for successful clinical applications.

Synergistic Activity of 3-Hydrazinoquinoxaline-2-Thiol in Combination with Penicillin Against MRSA

Background

The growing resistance seen in various antibiotics, including those considered as last-resort options, underscores the pressing need for novel approaches and new substances to address MRSA infections. Combining antibiotics as a treatment approach can enhance effectiveness, expand the range of targeted bacteria, and minimize the likelihood of resistance emergence. This approach holds promise in addressing the escalating issue of antibiotic resistance.

Purpose

This study seeks to investigate the potential synergy between 3-hydrazinoquinoxaline-2-thiol and penicillin against a diverse array of MRSA isolates, thereby providing insights into their combined antimicrobial action.

Methods

Twenty-two clinical MRSA isolates subjected to broth microdilution to determine the Minimum Inhibitory Concentrations (MICs) of 3-hydrazinoquinoxaline-2-thiol and penicillin. Subsequently, a checkerboard assay was employed to evaluate the interaction between 3-hydrazinoquinoxaline-2-thiol and penicillin, focusing on the Fractional Inhibitory Concentration Index (FICI).

Results

The MICs of penicillin and 3-hydrazinoquinoxaline-2-thiol were determined for 22 clinical MRSA strains. Penicillin exhibited MICs within a range of 1024 to 128 µg/mL, while 3-hydrazinoquinoxaline-2-thiol displayed MICs varying from 64 to 8 µg/mL. Remarkably, the combination of 3-hydrazinoquinoxaline-2-thiol and penicillin yielded a synergistic effect, resulting in a significant reduction of MICs by up to 64-fold.

Conclusion

The potential of 3-hydrazinoquinoxaline-2-thiol in combination with penicillin as a viable solution against MRSA appears promising. However, to establish its practical utility, further extensive testing and experiments are essential.

Actinomyces-induced Osteomyelitis of the Mandible - A Rare Disease

BACKGROUND

Actinomyces species are commensal oral cavity flora that can cause jaw osteomyelitis. Osteomyelitis of the jaw by Actinomyces is rare, and its presentation can be confused with many different pathologies.

CASE PRESENTATION

This is the case of a 61-year-old female with breast cancer and on chemotherapy as well as non-invasive carcinoma of the tongue who initially presented to the dentist with white spots in the right mandible near the incisors associated with right mandible pain and swelling. Actinomyces-induced osteomyelitis of the mandible was diagnosed. The patient was treated with penicillin V for 6 weeks along with a course of hyperbaric oxygen therapy, which resulted in the complete resolution of the infection.

CONCLUSION

In summary, jaw osteomyelitis caused by Actinomyces should always be part of the differential diagnosis; as these organisms are commensal flora, the symptoms manifested are nonspecific, and such a diagnosis could be easily missed, resulting in delay of care and disease progression.

Microwave-assisted synthesis and development of novel penicillinoate@copper metal-organic frameworks as a potent antibacterial agent

Recently, nanoscience, especially metal-organic frameworks (MOFs), has been used to increase the effectiveness and properties of drugs. In this study, by using microwave irradiation; penicillin, which is a known antibiotic; and copper metal-organic frameworks (Cu-MOFs), a new penicillinoate@copper metal-organic framework (penicillinoate@Cu-MOF) was synthesized. The structure and characterization of the newly synthesized compound were determined using FT-IR spectrums, EDAX analysis, elemental analysis, XRD patterns, SEM images, nitrogen adsorption/desorption curves, and TGA curve. Then, its antimicrobial effects were evaluated on numerous Gram-positive and Gram-negative bacterial strains and were compared with those of penicillin and gentamicin. In continuation of the biological activities, antioxidant tests were performed on the compounds using the DPPH method. For biological activities, the synthesized penicillinoate@Cu-MOF is much more effective than penicillin and Cu-MOF. The loading of penicillin on the nanostructure and the presence of copper in the final composition can be attributed to the high antibiotic properties of the synthesized composition.

Chemical immune conization of precancerous cervical lesions awakens immune cells and restores normal HPV negative and abnormal proliferation

Background

Cervical cancer is one of the most common and deadly cancers in women, which is closely linked to the persistent infection of high-risk human papillomavirus (HPV). Current treatment of cervical cancer involves radical hysterectomy, radiotherapy, and chemotherapy or a combination.

Objective

We investigated if hapten-enhanced intratumoral chemotherapy (HEIC) was effective in boosting immunity for effective treatment of precancerous cervical lesions and HPV infection.

Study design

We used single-cell RNA sequencing (scRNA-Seq) to obtain transcriptome profiles of 40,239 cells from biopsies of precancerous cervical lesions from the cervix directly from one patient before the start of HEIC and approximately 1 week after HEIC. The blood samples were taken at the same time as biopsies. We compared the expression characteristics of malignant epithelial cells and immune cells, including epithelial cells, endothelial cells (ECs), fibroblasts, mural cells, T cells, B cells, T and NK neutrophils, mast cells, microparticles (MPs), and platelets, as well as the dynamic changes in cell percentage and cell subtype heterogeneity.

Results

Intratumoral injection of chemotherapy drug plus hapten induces an acute immune response in precancerous cervical lesions with HPV and further awakens immune cells to prevent the abnormal proliferation of the precancerous cells.

Conclusion

HEIC provides a potential treatment method for cervical cancer and HPV infection tailored to each patient's condition.

Low-risk penicillin allergy delabeling: a scoping review of direct oral challenge practice, implementation, and multi-disciplinary approaches

INTRODUCTION

Penicillin allergy is common, and there is increased clinician interest in direct oral challenge (DOC) as a testing strategy for low-risk penicillin allergy. To aid wider implementation of DOC, consensus definitions of low-risk penicillin allergy phenotypes, and standardized approaches to assessment, DOC procedures, and evaluation, are required.

AREAS COVERED

This review systematically reviews studies that have utilized penicillin DOC in healthcare settings to identify heterogeneity in implementation approaches and synthesize low-risk definitions, procedures, and evaluation.

EXPERT OPINION

Opportunity exists to standardize penicillin DOC procedures in patients with a low-risk penicillin allergy to optimize antimicrobial prescribing and reduce the burden of penicillin allergy. Standardizing the definitions of 'low-risk' and 'positive challenge,' and improving the evaluation of patient safety, alongside the development of a unified approach to the structure of undertaking an oral challenge, is likely to increase uptake and confidence among non-allergist clinicians.

United States Drug Allergy Registry (USDAR) grading scale for immediate drug reactions

BACKGROUND

There is no accepted grading system classifying the severity of immediate reactions to drugs.

OBJECTIVE

The purpose of this article is to present a proposed grading system developed through the consensus of drug allergy experts from the United States Drug Allergy Registry (USDAR) Consortium.

METHODS

The USDAR investigators sought to develop a consensus severity grading system for immediate drug reactions that is applicable to clinical care and research.

RESULTS

The USDAR grading scale scores severity levels on a scale of 0 to 4. A grade of no reaction (NR) is used for patients who undergo challenge without any symptoms or signs, and it would confirm a negative challenge result. A grade 0 reaction is indicative of primarily subjective complaints that are commonly seen with both historical drug reactions and during drug challenges, and it would suggest a low likelihood of a true drug allergic reaction. Grades 1 to 4 meet the criteria for a positive challenge result and may be considered indicative of a drug allergy. Grade 1 reactions are suggestive of a potential immediate drug reaction with mild symptoms. Grade 2 reactions are more likely to be immediate drug reactions of moderate severity. Grade 3 reactions have features suggestive of a severe allergic reaction, whereas grade 4 reactions are life-threatening reactions such as anaphylactic shock and fatal anaphylaxis.

CONCLUSION

This proposed grading schema for immediate drug reactions improves on prior schemata by being developed specifically for immediate drug reactions and being easy to implement in clinical and research practice.

Is Penicillin Allergy a Clinical Problem? A Systematic Review of Total Joint Arthroplasty Procedures With Implications for Patient Safety and Antibiotic Stewardship

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) who report penicillin allergy (PA) are frequently administered second-line antibiotics, although recent evidence suggests that this may be unnecessary and could increase infection risk. Many institutions have aimed to improve antibiotic deployment via allergy testing and screening; however, there is little standardization to this process. This review aimed to evaluate (1) antibiotic selection in patients who report PA and assess the impact of screening and testing interventions, (2) rates of allergic reactions in patients who report PA, and (3) the association between reported PA and screening or testing programs and odds of surgical site infection or periprosthetic joint infection.

METHODS

PubMed, EBSCOhost, and Google Scholar electronic databases were searched on February 4, 2023 to identify all studies published since January 1, 2000 that evaluated the impact of PA on patients undergoing TJA (PROSPERO study protocol registration: CRD42023394031). Articles were included if full-text manuscripts in English were available, and the study analyzed the impact of PA and related interventions on TJA patients. There were 11 studies evaluating 1,276,663 patients included. Interventions were compared via presentation of key findings regarding rates of clinically relevant or high-risk PA reported upon screenings or testings, cephalosporin utilizations, allergic reactions, and postoperative infections (surgical site infection and periprosthetic joint infection).

RESULTS

All 6 studies found that PA screening and testing markedly increase the use of first-line antibiotics. Testing showed low rates of true allergy (0.7 to 3%) and allergic reaction frequency for patients who have reported PA receiving cephalosporins was between 0% and 2%. Although there were mixed findings across studies, there was a trend toward second-line antibiotic prophylaxis being associated with a slightly higher rate of infection in PA patients.

CONCLUSIONS

Using PA screening and testing can promote antibiotic stewardship by safely increasing the use of first-line antibiotics in patients who have a reported PA.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Predicting Beta-Lactam Target Non-Attainment in ICU Patients at Treatment Initiation: Development and External Validation of Three Novel (Machine Learning) Models

In the intensive care unit (ICU), infection-related mortality is high. Although adequate antibiotic treatment is essential in infections, beta-lactam target non-attainment occurs in up to 45% of ICU patients, which is associated with a lower likelihood of clinical success. To optimize antibiotic treatment, we aimed to develop beta-lactam target non-attainment prediction models in ICU patients. Patients from two multicenter studies were included, with intravenous intermittent beta-lactam antibiotics administered and blood samples drawn within 12-36 h after antibiotic initiation. Beta-lactam target non-attainment models were developed and validated using random forest (RF), logistic regression (LR), and naïve Bayes (NB) models from 376 patients. External validation was performed on 150 ICU patients. We assessed performance by measuring discrimination, calibration, and net benefit at the default threshold probability of 0.20. Age, sex, serum creatinine, and type of beta-lactam antibiotic were found to be predictive of beta-lactam target non-attainment. In the external validation, the RF, LR, and NB models confirmed good discrimination with an area under the curve of 0.79 [95% CI 0.72-0.86], 0.80 [95% CI 0.73-0.87], and 0.75 [95% CI 0.67-0.82], respectively, and net benefit in the RF and LR models. We developed prediction models for beta-lactam target non-attainment within 12-36 h after antibiotic initiation in ICU patients. These online-accessible models use readily available patient variables and help optimize antibiotic treatment. The RF and LR models showed the best performance among the three models tested.

Emergence of ciprofloxacin- and penicillin-resistant Neisseria meningitidis isolates in Japan between 2003 and 2020 and its genetic features

Although we previously reported that some meningococcal isolates in Japan were resistant to penicillin (PCG) and ciprofloxacin (CIP), the antibiotic susceptibilities of Neisseria meningitidis isolates obtained in Japan remained unclear. In the present study, 290 N. meningitidis isolates in Japan between 2003 and 2020 were examined for the sensitivities to eight antibiotics (azithromycin, ceftriaxone, ciprofloxacin, chloramphenicol, meropenem, minocycline, penicillin, and rifampicin). All isolates were susceptible to chloramphenicol, ceftriaxone, meropenem, minocycline, and rifampicin while two were resistant to azithromycin. Penicillin- and ciprofloxacin-resistant and -intermediate isolates (PCGR, CIPR, PCGI and CIPI, respectively) were also identified. Based on our previous findings from whole genome sequence analysis, approximately 40% of PCGI were associated with ST-11026 and cc2057 meningococci, both of which were unique to Japan. Moreover, the majority of ST-11026 meningococci were CIPR or CIPI. Sensitivities to PCG and CIP were closely associated with genetic features, which indicated that, at least for Japanese meningococcal isolates, PCGR/I or CIPI/R would be less likely to be horizontally conferred from other neisserial genomes by transferring of the genes responsible (penA and gyrA genes, respectively), but rather that ancestral N. meningitidis strains conferring PCGR/I or CIPI/R phenotypes clonally disseminated in Japan.

Delabeling, safety, and impact of β-lactam allergy testing: A systematic review

Background

To improve β-lactam delabeling outcomes, we need to understand current practice and the evidence base regarding its outcomes, safety, and impact.

Objectives

We sought to assess the existing published evidence reporting on the effectiveness of penicillin allergy testing and delabeling.

Methods

We conducted a systematic review of studies reporting β-lactam delabeling practices and outcomes after testing, including β-lactam use and patient understanding of the delabeling result. Searches of the PubMed, Scopus, and Embase databases; clinical trial registries; and websites of professional organizations were conducted. Data were extracted from the included studies in duplicate, with a third extraction if discrepancies remained.

Results

We included 284 publications (covering 98,316 participants); 173 were prospective studies, with no randomized controlled trials. The overall study quality was low. In all, 95.6% of individuals who underwent provocation testing were delabeled. Factors associated with successful delabeling could not be determined because of significant heterogeneity between studies. Anaphylaxis due to testing occurred in 0.3% of participants (95 of 31,667). Subjects who did not undergo skin testing (6,980 patients in 31 studies) before challenge had higher rates of provocation test positivity (8.8% vs 4.1% [P < .0001]) and anaphylaxis (15.9% vs 2.7% [P < .0001]) than those subjects who underwent skin testing (51,607 patients in 177 studies). Six studies (2.1%) followed patients after testing to assess their adherence to prescribing recommendations. In all, 136 participants (20.6%) were actively avoiding β-lactams despite delabeling.

Conclusions

The available data suggest that penicillin allergy testing is safe and effective in delabeling most individuals, but the evidence base is incomplete and more work is required to assess the role of skin testing and the impact that delabeling is having on prescribing habits.

The role of major and minor determinants in penicillin allergy testing: Time to revisit an old friend?

Background

Skin testing is an important step in evaluation of penicillin allergic reactions. It includes testing to the following: amoxicillin, benzyl penicillin, and products generated in vivo after penicillin administration, the major determinant hapten penicilloyl-polylysine (PPL) and the minor determinant mixture (MDM). Although PPL and MDM are available as a commercial kit, their supply and cost remain problematic.

Objective

We aimed to evaluate the performance and utility of PPL and MDM in penicillin allergy testing.

Methods

A retrospective audit over a 5-year period was undertaken for those with penicillin testing in a tertiary immunology unit.

Results

In all, 214 patients were identified. Of those patients, 151 (70.6%) were female and the average age was 58 years. Unspecified penicillin was the most common index drug (n = 127 [59.3%]), followed by amoxicillin (n =3 [24.8%]) and amoxicillin-clavulanic acid (n = 21 [9.7%]). The result of skin testing was positive in 23 patients (10.7%); skin prick testing was positive in 10 patients (4.7%), and intradermal testing (IDT) was positive in 13 patients (6.1%), the majority of whom had identified amoxicillin or amoxicillin-clavulanic acid as the index drug (n = 22 [95.7%]). The result of testing to PPL and/or MDM was positive with IDT only (n=5 [23.8%]). PPL and MDM positivity coexisted with a positive reaction to amoxicillin IDT in 2 patients, 1 of whom passed an amoxicillin challenge. Additionally, 2 positive tests to PPL were present with a negative result for MDM; of these 2 positive results, 1 was positive to amoxicillin IDT. In only 1 case were the results of testing for MDM and PPL both positive, with negative results to all native β-lactams tested; the patient tolerated an amoxicillin challenge. Overall, the negative predictive value for both skin prick testing and IDT was 89.5%.

Conclusion

Benzyl penicillin and amoxicillin alone may be sufficient for in vivo testing in suspected individuals with penicillin allergy.

Rolling the evolutionary dice: Neisseria commensals as proxies for elucidating the underpinnings of antibiotic resistance mechanisms and evolution in human pathogens

Species within the genus Neisseria are especially adept at sharing adaptive allelic variation across species' boundaries, with commensal species repeatedly transferring resistance to their pathogenic relative N. gonorrhoeae. However, resistance in commensal Neisseria is infrequently characterized at both the phenotypic and genotypic levels, limiting our ability to predict novel and potentially transferable resistance mechanisms that ultimately may become important clinically. Unique evolutionary starting places of each Neisseria species will have distinct genomic backgrounds, which may ultimately control the fate of evolving populations in response to selection, as epistatic and additive interactions may coerce lineages along divergent evolutionary trajectories. However alternatively, similar genetic content present across species due to shared ancestry may constrain the adaptive solutions that exist. Thus, identifying the paths to resistance across commensals may aid in characterizing the Neisseria resistome - or the reservoir of alleles within the genus, as well as its depth. Here, we use in vitro evolution of four commensal species to investigate the potential for and repeatability of resistance evolution to two antimicrobials, the macrolide azithromycin and the β-lactam penicillin. After 20 days of selection, commensals evolved elevated minimum inhibitory concentrations (MICs) to penicillin and azithromycin in 11/16 and 12/16 cases respectively. Almost all cases of resistance emergence converged on mutations within ribosomal components or the mtrRCDE efflux pump for azithromycin-based selection, and mtrRCDE or penA for penicillin selection; thus, supporting constrained adaptive solutions despite divergent evolutionary starting points across the genus for these particular drugs. However, continuing to explore the paths to resistance across different experimental conditions and genomic backgrounds, which could shunt evolution down alternative evolutionary trajectories, will ultimately flesh out the full Neisseria resistome.

Analysis of a beta-lactam allergy assessment protocol challenging diverse reported allergies managed by an antimicrobial stewardship program

Objective

To assess the safety and efficacy of a novel beta-lactam allergy assessment algorithm managed by an antimicrobial stewardship program (ASP) team.

Design

Retrospective analysis.

Setting

One quaternary referral teaching hospital and one tertiary care teaching hospital in a large western Pennsylvania health network.

Patients or participants

Patients who received a beta-lactam challenge dose under the beta-lactam allergy assessment algorithm.

Interventions

A beta-lactam allergy assessment protocol was designed and implemented by an ASP team. The protocol risk stratified patients' reported allergies to identify patients appropriate for a challenge with a beta-lactam antibiotic. This retrospective analysis assessed the safety and efficacy of this protocol among patients receiving a challenge dose from November 2017 to July 2021.

Results

Over a 45-month period, 119 total patients with either penicillin or cephalosporin allergies entered the protocol. Following a challenge dose, 106 (89.1%) patients were treated with a beta-lactam. Eleven patients had adverse reactions to a challenge dose, one of which required escalation of care to the intensive care unit. Of the patients with an unknown or low-risk reported allergy, 7/66 (10.6%) had an observed adverse reaction compared to 3/42 (7.1%) who had an observed reaction with a reported high-risk or anaphylactic allergy.

Conclusions

Our implemented protocol was safe and effective, with over 90% of patients tolerating the challenge without incident and many going on to receive indicated beta-lactam therapy. This protocol may serve as a framework for other inpatient ASP teams to implement a low-barrier allergy assessment led by ASP teams.

Demystifying Ocular Syphilis - A Major Review

Syphilis, caused by the spirochaete, Treponema pallidum, continues to be a public health challenge globally with its rates steadily increasing in the past few years. The disease is transmitted through small breaks in the skin during sexual contact, or via congenital transmission in utero, either across the placenta or by contact with an active genital lesion during delivery. Estimated 5.7-6 million new cases are detected every year worldwide in the 15-49 years age group. An increased incidence has been reported in most populations with particular clusters in special groups like men who have sex with men, female sex workers, and their male clients. Ocular syphilis has a varied presentation and is considered a great mimicker in all cases of uveitis. The laboratory diagnosis of syphilis is predominantly based on serological tests including TPHA and VDRL. Parenteral penicillin is the cornerstone of treatment for all stages of ocular syphilis.

The impact of Post-Transplant doxycycline in AL amyloidosis - updated results after Long-Term follow up

INTRODUCTION

The current treatment paradigm of AL amyloidosis lacks effective fibril-directed therapies. Doxycycline has been shown to have anti-fibril properties in preclinical models. In 2012, we reported that posttransplant prophylaxis with doxycycline was associated with improved survival compared to penicillin in patients with haematologic response. We provide here updated results after long-term follow up.

METHODS

We included 553 patients who underwent transplant between July 24th, 1996, and June 24th, 2014. Doxycycline 100 mg daily was used for prophylaxis in patients with penicillin allergy; since 2013, doxycycline was used as the standard for prophylaxis. Prophylaxis was typically continued for a year after transplant.

RESULTS

The median follow-up from transplant was 12.7 years. Doxycycline was used for prophylaxis in 33% of patients; the rest received penicillin. The median time to next treatment was 6.0 (95%CI; 4.4-8.8) years and 6.0 (95%CI; 4.9-7.1) years in the doxycycline and penicillin groups, respectively (p = .89). The median overall survival was 12.0 (95%CI: 11.0-19.6) years and 11.0 (95%CI: 9.6-12.7) years in the 2 groups, respectively (p = .17). There was a minimal trend towards improved survival with doxycycline among patients with ≥ very good partial response and among patients with organ response that was not statistically significant.

CONCLUSION

After long-term follow-up, there is no clear evidence to support benefit of doxycycline in the post-transplant setting.

Antimicrobial susceptibility of staphylococci from bovine milk samples in routine microbiological mastitis analysis in Finland

The most frequent reason for antimicrobial use in dairy herds is mastitis and knowledge about mastitis-causing pathogens and their antimicrobial susceptibility should guide treatment decisions. The overall objective of this study was to assess antimicrobial resistance (AMR) of staphylococci in mastitic milk samples in Finland. MALDI-ToF MS identified a total of 504 Staphylococcus isolates (260 S. aureus and 244 non-aureus staphylococci, NAS) originating from bovine mastitic milk samples. Phenotypic susceptibility against cefoxitin, ceftiofur, enrofloxacin, gentamycin, oxacillin, penicillin, and tetracycline was evaluated by disk diffusion method and the presence of blaZ, mecA, and mecC genes investigated by PCR. Nitrocefin test assessed these isolates' beta-lactamase production. The most common NAS species were S. simulans, S. epidermidis, S. chromogenes, and S. haemolyticus. In total, 26.6% of the isolates (18.5% of S. aureus and 35.2% of all NAS) carried the blaZ gene. Penicillin resistance, based on disk diffusion, was lower: 18.8% of all the isolates (9.3% of S. aureus and 28.9% of all NAS) were resistant. Based on the nitrocefin test, 21.5% of the isolates produced beta-lactamase (11.6% of S. aureus and 32.0% of all NAS). Between the Staphylococcus species, the proportion of penicillin-resistant isolates varied, being lowest in S. simulans and highest in S. epidermidis. Resistance to antimicrobials other than penicillin was rare. Of the eight NAS isolates carrying the mecA gene, six were S. epidermidis. One S. aureus isolate carried the mecC gene. Agreement beyond chance, assessed by kappa coefficient, between phenotypic and genotypic resistance tests, was moderate to substantial. Some phenotypically penicillin-susceptible staphylococci carried the blaZ gene but isolates without blaZ or mec genes rarely exhibited resistance, suggesting that the more reliable treatment choice may depend upon genotypic AMR testing. Our results support earlier findings that penicillin resistance is the only significant form of antimicrobial resistance among mastitis-causing staphylococci in Finland.

Machine learning models automate classification of penicillin adverse drug reaction labels

There is a growing interest in the appropriate evaluation of penicillin adverse drug reaction (ADR) labels. We have developed machine learning models for classifying penicillin ADR labels using free-text reaction descriptions, and here report external and practical validation. The models performed comparably with expert criteria for the categorisation of allergy or intolerance and identification of high-risk allergies. These models have practical applications in detecting individuals suitable for penicillin ADR evaluation. Implementation studies are required.

Warfarin and Antibiotics: Drug Interactions and Clinical Considerations

Warfarin administration poses a notable challenge in clinical practice due to the increased susceptibility of patients to major bleeding, particularly when co-administered with other medications capable of modulating its metabolic pathways. Among these medications, antibiotics have been recognized as potential agents that can either induce or inhibit cytochrome P450-2C9, thereby impacting the effects of warfarin. A wealth of evidence from numerous studies consistently supports an elevated risk of serious bleeding in patients concurrently receiving antibiotics and warfarin therapy. This narrative review elucidates the intricate interactions between warfarin and various antibiotic classes. Notably, significant increases in the International Normalized Ratio (INR) were observed among warfarin-treated patients receiving penicillin derivatives, fluoroquinolones, TMP-SMX, and macrolides. Conversely, investigations have also demonstrated a reduction in INR levels in patients on warfarin when exposed to rifampin, a potent inducer of cytochrome P-450. Intriguingly, cephalosporin antibiotics and amoxicillin/clavulanate, despite not interfering with the cytochrome P450 system, exhibited a positive association with increased INR values. The findings of this narrative review underscore the importance of diligent monitoring in patients on warfarin requiring concomitant antibiotic therapy, as this surveillance strategy proves pivotal in mitigating the risk of major bleeding complications. Additionally, for patients necessitating cytochrome P450 inhibitors such as penicillin derivatives, fluoroquinolones, TMP-SMX, and macrolides, the consideration of dose reduction in warfarin therapy may confer substantial benefits in reducing the occurrence of major bleeding events. Similarly, patients who are co-administered rifampin alongside warfarin necessitate vigilant monitoring, with a potential need for escalating warfarin doses to counteract the risk of a hypercoagulable state.

COVID-19 and Listeria Meningitis Treated by Ampicillin, Sulfamethoxazole/Trimethoprim and Meropenem

Background

Secondary bacterial infection was initially rare in SARS-CoV-2 infectious disease (COVID-19) patients, but COVID-19-associated bacterial infectious diseases have recently been increasing. Furthermore, it might be difficult to distinguish COVID-19 from bacterial meningitis by the symptoms, and one might be uncertain about antibiotic therapy for Listeria meningitis infection-typically caused by eating contaminated food-in elderly persons and pregnant women.

Case Report

A 96-year-old woman who had been living alone was found to have SARS-CoV-2 infection in February 2023. She was admitted to our hospital with high fever and disturbance of consciousness and was started on treatment with remdesivir. Two days later, her consciousness was still disturbed, and she was found to have a stiff neck. In addition, increased white blood cell counts and C-reactive protein suggested bacterial infection. Therefore, a lumbar puncture was done, and Listeria monocytogenes was ultimately isolated from blood cultures and its genetic material was detected in cerebrospinal fluid. She had previously eaten refrigerated food and cheese products. Intravenous ampicillin 1.0 g 6×/day was started, but one week later, loss of consciousness continued, and the cerebrospinal findings were not improved, although nasal swab became negative for SARS-CoV-2. Intravenous sulfamethoxazole/trimethoprim (ST) 80/400 mg 3×/day was added, and her consciousness and fever improved by one week later. A drug rash appeared after ST was started, and she was switched to meropenem. Her condition finally improved.

Conclusion

COVID-19-associated secondary listeria infection was found in an elderly woman. She was treated with not only ampicillin, but also ST and meropenem. Meningitis caused by Listeria monocytogenes should be considered as a secondary complication and carefully treated with antibiotics during the period of the COVID-19 pandemic.

Data-Driven Two-Stage Framework for Identification and Characterization of Different Antibiotic-Resistant Escherichia coli Isolates Based on Mass Spectrometry Data

In clinical microbiology, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is frequently employed for rapid microbial identification. However, rapid identification of antimicrobial resistance (AMR) in Escherichia coli based on a large amount of MALDI-TOF MS data has not yet been reported. This may be because building a prediction model to cover all E. coli isolates would be challenging given the high diversity of the E. coli population. This study aimed to develop a MALDI-TOF MS-based, data-driven, two-stage framework for characterizing different AMRs in E. coli. Specifically, amoxicillin (AMC), ceftazidime (CAZ), ciprofloxacin (CIP), ceftriaxone (CRO), and cefuroxime (CXM) were used. In the first stage, we split the data into two groups based on informative peaks according to the importance of the random forest. In the second stage, prediction models were constructed using four different machine learning algorithms-logistic regression, support vector machine, random forest, and extreme gradient boosting (XGBoost). The findings demonstrate that XGBoost outperformed the other four machine learning models. The values of the area under the receiver operating characteristic curve were 0.62, 0.72, 0.87, 0.72, and 0.72 for AMC, CAZ, CIP, CRO, and CXM, respectively. This implies that a data-driven, two-stage framework could improve accuracy by approximately 2.8%. As a result, we developed AMR prediction models for E. coli using a data-driven two-stage framework, which is promising for assisting physicians in making decisions. Further, the analysis of informative peaks in future studies could potentially reveal new insights. IMPORTANCE Based on a large amount of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) clinical data, comprising 37,918 Escherichia coli isolates, a data-driven two-stage framework was established to evaluate the antimicrobial resistance of E. coli. Five antibiotics, including amoxicillin (AMC), ceftazidime (CAZ), ciprofloxacin (CIP), ceftriaxone (CRO), and cefuroxime (CXM), were considered for the two-stage model training, and the values of the area under the receiver operating characteristic curve (AUC) were 0.62 for AMC, 0.72 for CAZ, 0.87 for CIP, 0.72 for CRO, and 0.72 for CXM. Further investigations revealed that the informative peak m/z 9714 appeared with some important peaks at m/z 6809, m/z 7650, m/z 10534, and m/z 11783 for CIP and at m/z 6809, m/z 10475, and m/z 8447 for CAZ, CRO, and CXM. This framework has the potential to improve the accuracy by approximately 2.8%, indicating a promising potential for further research.

Down-Syndrome-Related Maternal Dysbiosis Might Be Triggered by Certain Classes of Antibiotics: A New Insight into the Possible Pathomechanisms

Down syndrome (DS) is a leading human genomic abnormality resulting from the trisomy of chromosome 21. The genomic base of the aneuploidy behind this disease is complex, and this complexity poses formidable challenges to understanding the underlying molecular basis. In the spectrum of the classic DS risk factor associations, the role of nutrients, vitamins, and, in general, the foodborne-associated background, as part of the events ultimately leading to chromosome nondisjunction, has long been recognized as a well-established clinical association. The integrity of the microbiome is a basic condition in these events, and the dysbiosis may be associated with secondary health outcomes. The possible association of DS development with maternal gut microbiota should therefore require more attention. We have hypothesized that different classes of antibiotics might promote or inhibit the proliferation of different microbial taxa; and hence, we might find associations between the use of the different classes of antibiotics and the prevalence of DS through the modification of the microbiome. As antibiotics are considered major disruptors of the microbiome, it could be hypothesized that the consumption/exposure of certain classes of antibiotics might be associated with the prevalence of DS in European countries (N = 30). By utilizing three different statistical methods, comparisons have been made between the average yearly antibiotic consumption (1997-2020) and the estimated prevalence of people living with DS for the year 2019 as a percentage of the population in European countries. We have found strong statistical correlations between the consumption of tetracycline (J01A) and the narrow-spectrum, beta-lactamase-resistant penicillin (J01CF) and the prevalence of DS.

Penicillin-Susceptible Streptococcus pneumoniae Meningitis in Adults: Does the Ceftriaxone Dosing Matter?

The recommended empiric ceftriaxone dosing regimen for acute bacterial meningitis in adults is 2 g every 12 h. After penicillin-susceptible Streptococcus pneumoniae is isolated as a causative microorganism, the ceftriaxone dose may be continued or reduced to a single dose of 2 g every 24 h, per institutional preference. There is no clear guidance that indicates the superiority of one regimen over the other. The objective of this study was to evaluate the susceptibility of S. pneumoniae in the cerebral spinal fluid (CSF) of patients with meningitis and the relationship between ceftriaxone dose and clinical outcomes. We identified 52 patients with S. pneumoniae meningitis with positive CSF cultures who were treated at the University Hospital, Bern, Switzerland, over a 19-year period. We collected clinical and microbiological data for evaluation. Broth microdilution and Etest methods were performed to test penicillin and ceftriaxone susceptibility. All isolates were susceptible to ceftriaxone. Ceftriaxone was empirically used in 50 patients, with a starting dosing regimen of 2 g every 24 h in 15 patients and 2 g every 12 h in 35 patients. In 32 patients started on a twice-daily regimen (91%), doses were reduced to once daily after a median of 1.5 (95% CI 1-2) days. The overall in-hospital mortality was 15.4% (n = 8), and 45.7% of patients reported at least one sequela of meningitis at the last follow-up (median 375, 95% CI 189-1585 days). We found no statistical difference in outcome between the 2 g every 24 h and the 2 g every 12 h ceftriaxone dosing regimens. A ceftriaxone total daily dose of 2 g may be associated with similar outcomes to a 4 g total daily dose, provided that the causative organism is highly susceptible to ceftriaxone. The persistence of neurological and infection sequelae at the last follow-up underscores the need for optimal treatment of these complex infections.

Unique Presentation of Syphilis With Ocular Involvement: A Case Report

Ocular syphilis could be the first sign of undiagnosed syphilis. In addition to otosyphilis, it can be observed in the primary, secondary, or tertiary stages of syphilis. Nonspecific clinical symptoms make diagnosis difficult. We report a patient who presented with generalized weakness and blurry vision for the past four to five days. In this case, we emphasize the importance of repeated cerebrospinal fluid (CSF) examinations as they led to the diagnosis of ocular syphilis and appropriate neurosyphilis treatment. It must be suspected in patients with primary or secondary neurological symptoms, such as blurred vision and weakness. Treponema, the causative organism, is invisible under light microscopy and is mostly identified by its distinct spiral movements under darkfield microscopy. Once the diagnosis was made, the patient was started on penicillin treatment to prevent spread to the brain and dorsal spinal cord. The patient responded well to antibiotic treatment, with improvement in visual acuity, and was discharged with close neurological and ophthalmological follow-up.

[The mysterious Soviet producer]

The article, using published materials on the history of the Soviet scientific technical intelligence and declassified documents of the Russian archives and the CIA archive, considers issue of the producer applied to start the production of penicillin in the USSR. Currently, dosage of published information, limitation of archival data and specificity of foreign sources makes it impossible to clarify this issue once and for all. However, the article presents number of arguments indirectly indicating likelihood of launching into production penicillin strain procured in the USA by intelligence agent S. M. Semenov.

Periconceptional antibiotic use and spontaneous abortion: A prospective cohort study

BACKGROUND

Many reproductive-aged North Americans use antibiotics in the weeks preceding conception or during early pregnancy. Antibiotic use may influence risk of spontaneous abortion (SAB) by disrupting the reproductive tract microbiome or treating harmful infections. However, this association has not been extensively studied.

OBJECTIVE

To determine the extent to which periconceptional antibiotic use is associated with the risk of SAB.

METHODS

We analysed data from an internet-based preconception cohort study of pregnancy planners. Eligible participants self-identified as female, were aged 21-45 years, resided in the USA or Canada, and conceived during 12 months of follow-up (n = 7890). Participants completed an enrolment questionnaire during June 2013-September 2021 and bimonthly follow-up questionnaires for up to 12 months or until a reported pregnancy, whichever came first. Pregnant participants completed questionnaires in early (~8-9 weeks) and late (~32 weeks) gestation. We assessed antibiotic use, including type (penicillins, nitrofurantoin, cephalosporins and macrolides) and indication for use, during the previous 4 weeks on preconception questionnaires. Participants reported pregnancies and SAB on follow-up and pregnancy questionnaires. We used Cox proportional hazards regression models with gestational weeks as the time scale to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between periconceptional antibiotic use and SAB, controlling for potential demographic, medical, and lifestyle confounders.

RESULTS

Nineteen percent (n = 1537) of pregnancies ended in SAB. Participants reported periconceptional antibiotic use in 8% of pregnancies ending in SAB and 7% not ending in SAB. Periconceptional antibiotic use was not appreciably associated with SAB (adjusted HR 1.06, 95% CI 0.88, 1.28). We observed no strong associations between antibiotic type, indication for use, or recency of exposure and SAB risk.

CONCLUSIONS

Periconceptional antibiotic use was not appreciably associated with SAB in this study. This association is likely complicated by antibiotic type and dosage, timing of conception, and the individual's overall health.

Impact of Penicillin Allergy Labels on Children Treated for Outpatient Respiratory Infections

BACKGROUND

Penicillin allergy is the most common antibiotic allergy, yet most children labeled as allergic tolerate penicillin. The impact of inaccurate penicillin allergy labels (PALs) on pediatric outpatients is unknown. The objective of this study was to compare outcomes between children with and without a PAL after treatment for outpatient respiratory tract infections (RTI).

METHODS

A retrospective, longitudinal birth cohort study was performed in children who received care in 90 pediatric primary care practices in Philadelphia and Houston metropolitan areas. Prescribing and clinical outcomes of children with a PAL at the time of an RTI were compared to non-allergic children, adjusting for potential confounders.

RESULTS

Antibiotics were prescribed for 663,473 non-recurrent RTIs among 200,977 children. Children with a PAL (5% of cohort) were more likely than non-allergic children to receive broad-spectrum antibiotics (adjusted relative risk (aRR) 3.24, 95% CI 3.22-3.26) and second-line antibiotics (aRR 4.87, 95% CI 4.83, 4.89). Compared to non-allergic children receiving first-line antibiotics, children with a PAL were more likely to return with adverse drug events (aRR 1.28, 95% CI 1.18-1.39). There was no difference in treatment failure between groups (aRR 0.95, 95% CI 0.90-1.00).

CONCLUSIONS

PALs lead to higher rates of broad-spectrum and second-line antibiotic prescribing in children treated for RTIs in primary care and contribute to unnecessary healthcare utilization through increased adverse events. Given the frequency of PALs, efforts to prevent inappropriate penicillin allergy labeling and promote de-labeling of existing inaccurate allergy labels may improve care of children treated for common bacterial infections.

Artificial intelligence and the potential for perioperative delabeling of penicillin allergies for neurosurgery inpatients

PURPOSE OF THE ARTICLE

Patients with penicillin allergy labels are more likely to have postoperative wound infections. When penicillin allergy labels are interrogated, a significant number of individuals do not have penicillin allergies and may be delabeled. This study was conducted to gain preliminary evidence into the potential role of artificial intelligence in assisting with perioperative penicillin adverse reaction (AR) evaluation.

MATERIAL AND METHODS

A single-centre retrospective cohort study of consecutive emergency and elective neurosurgery admissions was conducted over a two-year period. Previously derived artificial intelligence algorithms for the classification of penicillin AR were applied to the data.

RESULTS

There were 2063 individual admissions included in the study. The number of individuals with penicillin allergy labels was 124; one patient had a penicillin intolerance label. Of these labels, 22.4% were not consistent with classifications using expert criteria. When the artificial intelligence algorithm was applied to the cohort, the algorithm maintained a high level of classification performance (classification accuracy 98.1% for allergy versus intolerance classification).

CONCLUSIONS

Penicillin allergy labels are common among neurosurgery inpatients. Artificial intelligence can accurately classify penicillin AR in this cohort, and may assist in identifying patients suitable for delabeling.

[Nicolau syndrome]

Nicolau syndrome is a rare complication of the parenteral application of various drugs. It is characterized by the appearance of pain, followed by edema, erythema, and then a necrotic plaque. We present the case of a 31-year-old male with this syndrome, after the application of intramuscular benzathine penicillin. The diagnosis was supported by the biopsy. He received treatment with enoxaparin and cilostazol with subsequent improvement.

Distribution of Multidrug-Resistant Invasive Serotypes of Streptococcus pneumoniae during the Period 2007-2021 in Madrid, Spain

After the systematic use of conjugate vaccines, the invasive pneumococcal disease (IPD) was included into the Madrid Notifiable Diseases Surveillance System through an Epidemiological Surveillance Network. Furthermore, Streptococcus pneumoniae was included in the Spanish Plan of Antibiotic Resistance. The aim of this study was to analyse the multidrug-resistant (MDR) phenotype distribution among invasive strains of Streptococcus pneumoniae isolated during 2007-2021 from usually sterile clinical samples in Madrid, Spain. A total number of 7133 invasive pneumococcal isolates were studied during the period from February 2007 to December 2021. Serotyping was characterised using the Pneumotest-Latex and by the Quellung reaction. Antibiotic susceptibility testing to penicillin (PEN), erythromycin (ERY), and levofloxacin (LVX) was performed using the E-test according to the EUCAST guidelines and breakpoints. Combination of non-susceptibility to PEN at standard dosing regimen (PNSSDR), resistance to ERY (ERYR) and to LVX (LVXR) was considered to be multidrug-resistant at standard dosing regimen of penicillin (MRPSDR), whereas the combination of resistance to PEN (PENR), ERYR, and LVXR was considered multidrug-resistant (MDR). The number of MDRPSDR and or MDR strains in the entire population (n = 7133) during the complete period (2007-2021) were 51 (0.7%) and 6 (0.1%), respectively. All MDRPSDR and/or MDR strains belonged to nine serotypes: 19A (n = 13), 15A (n = 12), 9V (n = 12), 14 (n = 7), 24F (n = 3), 15F (n = 1), 19F (n = 1), 6B (n = 1) and 6C (n = 1). Only two serotypes (9V and 19A) were found among MDR strains, and most of them (5/6) belonged to serotype 9V. Only 12.4% of the strains typified as serotype 9V were MDRPSDR and only 5.2% as MDR. The levels of pneumococcal MDRPSDR and/or MDR in this study were low and all six MDR strains were isolated between 2014 and 2018. These results reinforce the importance of monitoring the evolution of non-susceptible serotypes including those with MDR in the coming years, especially after the introduction of new conjugate vaccines of a broader spectrum.

Professor George Archibald Grant Mitchell (1906-1993): his work with penicillin during World War II

George Archibald Grant Mitchell, OBE, TD, MB, ChB, ChM, MSc, DSc, FRCS (1906-1993) was a professor of anatomy at the University of Manchester from 1946 to 1973. He is mainly remembered for his research in neuroanatomy, especially of the autonomic nervous system. He studied medicine at the Aberdeen University, and after qualifying in 1929 he held posts in surgery and anatomy and worked as a surgeon in the Highlands. In 1939, he joined the Royal Army Medical Corps. He was based in Egypt and the Middle East, where he carried out trials of sulphonamides and penicillin on wounded soldiers; in 1943, he returned to England as Adviser in Penicillin Therapy for 21 Army Group, preparing for the invasion of Europe.

Evolution of Antimicrobial Susceptibility to Penicillin in Invasive Strains of Streptococcus pneumoniae during 2007-2021 in Madrid, Spain

The use of pneumococcal conjugate vaccines has affected the epidemiology and distribution of Streptococcus pneumoniae serotypes causing Invasive Pneumococcal Disease (IPD). The aim of this study was to analyze the evolution of the phenotypical profiles of antimicrobial susceptibility to penicillin (PEN) in all IPD strains isolated in Madrid, Spain, during 2007-2021. In total, 7133 invasive clinical isolates were characterized between 2007 and 2021. Levels of PENR and PNSSDR were 2.0% and 24.2%, respectively. In addition, 94.4% of all the PENR belonged to four serotypes, including 11A (33.6%), 19A (30.8%), 14 (20.3%) and 9V (9.8%). All the strains of serotype 11A, which is a non-PCV13 serotype, were detected after the year 2011. Serotypes 6C, 15A, 23B, 24F, 35B, 19F, 16F, 6B, 23F, 24B, 24A, 15F and a limited number of strains of serogroups 16 and 24 (non-typed at serotype level) were associated with PNSSDR (p < 0.05). PNSSDR strains of non-PCV13 serotypes 11A, 24F, 23B, 24B, 23A and 16F were more frequent from 2014 to 2021. The changes in S. pneumoniae serotype distribution associated with the use of conjugate vaccines had caused in our region the emergence of non-PCV13 pneumococcal strains with different PENR or PNSSDR patterns. The emergence of serotype 11A resistant to penicillin as the most important non-PCV13 serotype is a worrisome event with marked relevance from the clinical and epidemiological perspective.

Penicillin and Cefotaxime Resistance of Quinolone-Resistant Neisseria meningitidis Clonal Complex 4821, Shanghai, China, 1965-2020

Clonal complex 4821 (CC4821) Neisseria meningitidis, usually resistant to quinolones but susceptible to penicillin and third-generation cephalosporins, is increasing worldwide. To characterize the penicillin-nonsusceptible (PenNS) meningococci, we analyzed 491 meningococci and 724 commensal Neisseria isolates in Shanghai, China, during 1965-2020. The PenNS proportion increased from 0.3% in 1965-1985 to 7.0% in 2005-2014 and to 33.3% in 2015-2020. Of the 26 PenNS meningococci, 11 (42.3%) belonged to the CC4821 cluster; all possessed mutations in penicillin-binding protein 2, mostly from commensal Neisseria. Genetic analyses and transformation identified potential donors of 6 penA alleles. Three PenNS meningococci were resistant to cefotaxime, 2 within the CC4821 cluster. With 96% of the PenNS meningococci beyond the coverage of scheduled vaccination and the cefotaxime-resistant isolates all from toddlers, quinolone-resistant CC4821 has acquired penicillin and cefotaxime resistance closely related to the internationally disseminated ceftriaxone-resistant gonococcal FC428 clone, posing a greater threat especially to young children.

Going Back in Time: Increasing Penicillin Susceptibility among Methicillin-Susceptible Staphylococcus aureus Osteoarticular Infections in Children

In the late 1940s to 1950s, Staphylococcus aureus isolates first-gained resistance to penicillin. Recently, some centers have described an increase in the proportion of methicillin susceptible S. aureus (MSSA) which are also susceptible to penicillin (PSSA). There are little data on the frequency of PSSA infections in children. We investigated the prevalence of penicillin susceptibility among pediatric MSSA acute hematogenous osteoarticular infection (OAI) isolates. MSSA OAI isolates were obtained through surveillance studies at Texas Children's and St. Louis Children's Hospitals from January 2011 to December 2019. All isolates underwent PCR for blaZ β-lactamase, PVL genes and agr group. All blaZ negative isolates then underwent penicillin MIC determination. blaZ negative isolates with penicillin MIC ≤ 0.125 μg/mL were considered PSSA. Multilocus sequence typing (MLST) was conducted on a subset of isolates. A total of 329 unique isolates were included in the study. The median patient age was 9.2 years (IQR:5.1 to 12.2). Overall, 6.7% of isolates were penicillin susceptible. No PSSA were detected prior to 2015 but increased yearly thereafter. By the final study year, 20.4% of isolates were PSSA (P = 0.001). PSSA were similar to penicillin-resistant MSSA (PR-MSSA) isolates in terms agr group and PVL carriage as well as clinical presentation and outcomes. PSSA were of distinct sequence types compared to PR-MSSA. PSSA appears to be increasing among OAI in U.S. children. Overall, PSSA isolates are associated with a similar clinical presentation as penicillin-resistant isolates. The potential for use of penicillin treatment in PSSA OAI warrants further study.

[The international cooperation in organizing penicillin production in the USSR]

The article considers interaction of the USSR with foreign scientists and international organizations in the process of mastering production of penicillin and establishment of penicillin industry. The analysis of archival documents demonstrated that despite influence of unfavorable foreign policy factors, various forms of this interaction were one of the decisive conditions of establishment of large-scale antibiotic production in the USSR by the end of the 1940s.